Hydrocarbons, Crude Oil, Alkanes, Alkenes(Organic Chemistry Part 1) Flashcards
What is an organic compound
A compound which contains carbon
What is a hydrocarbon
A molecule
that consists of hydrogen and carbon atoms
ONLY
Why are molecular formulas rarely used in organic chemistry
Because they do not show anything about the bonding in a molecule
Definition of homologous series
Group of organic compounds
That have similar chemical properties
BECAUSE they have the same functional group
What is a functional group
An atom or group of atoms that determine the chemical properties of a compound
Molecular formula definition
Actual number of atoms in a molecule
Structural isomer definition
Molecule with the same molecular formula but different structural formula
A student carries out an experiment with pentanoic acid. If she uses another carboxylic acid to carry out the same experiment, will it react the same or differently and why
Will react the same because compounds in the same homologous series react in similar ways due to having the same functional group
If I have an isomer with a different functional group, will it have the same or different chemical and physical properties?
Different
Which alkanes do not have isomers and which do
Methane, ethane, propane
But butane does
What is the order of alkanes
Methane, ethane, propane, butane
What is the functional group of an alcohol
-OH
(Hydroxyl group)
What is the functional group of a carboxyl acid
-COOH
(Carboxyl group)
What is the functional group of an alkane
And an alkene
Alkane—-) C-C
Alkene—-) C=C
Name the order of alkenes
Ethene
Propene
Butene
Discuss alkenes and their isomers
Ethene does not have isomers
And propene does not have isomers which are alkenes(because they have no carbon-carbon double bond)
What is the general formula of an alkene
CnH2n
General formula of an alkane
CnH2n+2
Are alkanes saturated or unsaturated
Saturated
(Single bonds)
General formula of Alkane and Alkene
Alcohol and Carboxylic acid
ALKANE: ALKENE:
CnH2n+2 CnH2n
ALCOHOL: Carboxylic acid
CnH2n+1OH CnH2nO2
How was crude oil formed
From the remains of marine animals over millions of years
Explain the volatility of hydrocarbons as their chain length increases
Volatility is how easily it evaporates
So as chain length increases
Volatility increases because
Intermolecular forces of attraction are stronger so less likely to evaporate into a gas
Describe how five physical properties of hydrocarbons change as chain length increases
Becomes more viscous
Boiling point increases
Becomes darker
Becomes less volatile
Becomes less likely to burn
Give one reason why when it comes to combustion of hydrocarbons, smaller chain molecules are better to use than larger chain molecules
Because smaller chain molecules burn more easily
Give a property of ethane and propane that show they are in the same homogenous group
The same general formula
What is a fraction
Groups of hydrocarbons
With similar chain length
And with similar boiling points
What is crude oil
a mixture
of hydrocarbons
Of different chain lengths
How does bitumen form
Contains very large chain Hydrocarbons
And boiling point is too high to be boiled (into a vapour at the start of the process)
So remains a liquid
And is released through the fractionating column and used to make bitume.
What is petroleum another word for
Crude oil
Fill in the gaps:
When the hydrocarbons reach part of the column where the temperature is …. than their … they… into a…
lower
Boiling
Condense
Liquid
Explain what happens to long hydrocarbons during fractional distillation
They have long chain lengths
And so high boiling points
So remain at the bottom of the column
And condense earlier on
Because much hotter at the bottom
Why do large chain hydrocarbons condense earlier than when short chain hydrocarbons condense
Because the column is much hotter at the bottom
And long chain hydrocarbons are condensed there
As they have higher boiling points
Explain what happens to short chain hydrocarbons during fractional distillation
They are have shorter hydrocarbon chain lengths
And so have low boiling points
And so condense at the top of the column
Later on
Because it is much cooler
What aspect of the factional distillation column allows gases to be condensed at different times
The temperature gradient
Does each fraction in fractional distillation column have saturated or unsaturated hydrocarbons
May have either
Why does the top of the column have gases taken from them
Because these are very short chain molecules
Which have very low boiling points
And the fractionating column is not cool enough the condense these into liquid
So they remain in gas form
Explain the process of fractional distillation of crude oils:
1)Crude oil is boiled so that it vaporizes into a gas
2)liquid part called bitumen is drained out + colum contains temperature gradient
3)So vapors rise and longest hydrocarbon chain, condenses into a liquid first, as highest boiling points, at the bottom of the column as it is the hottest,
4)shortest hydrocarbon chains condense into a liquid last, as lowest boiling points, at the top of the column, as it is coolest,
5)vapors with very short hydrocarbon chains do not condense because very low boiling points and so are collected at the top as gases
6) bubble caps separate the Fractions + prevent the vapour from falling down, and mixing with others
The boiling point can also be referred to as:
The condensation point
Because boiling is just the opposite of condensation
(So it occurs at the same point)
What is another word for petrol
Gasoline
What is paraffin often referred as
Kerosene
Give six names of the fractions in fractional distillation and their uses
(From top to bottom)
Refinery gases—) domestic heating and cooking
Petrol—) fuel for cars
Kerosene—) fuel for jet planes + paraffin for small lamps
Diesel oil—) fuel for buses, lorries
Fuel oil—) fuel for ships + industrial heating
Bitumen—-) surfacing roads
Which fraction has larger hydrocarbon chain length
Kerosene or fuel oil?
Fuel oil
Which fraction has smaller hydrocarbon chain length?
Diesel oil or petrol
Petrol
Which molecules are refinery gases a mixture of?
Methane, ethane, propane, butane
Which is more viscous and explain why
Kerosene or diesel oil?
And why?
Diesel oil
Because larger hydrocarbon chain length
and so stronger intermolecular forces of attraction
So flow less easily
Which is less volatile?
Fuel oil or petrol?
And why
Fuel oil
Because larger hydrocarbon chain length
So stronger intermolecular forces of attraction
So more difficult to evaporate into a gas
Why does the fractionating column contain bubble traps
To prevent the fractions from mixing
What is a fuel?
A substance that when burned, releases heat energy
What is one of the major hydrocarbons present in petrol?
Octane